Is the abohm still used today?

No, it is an obsolete unit from the cgs system, completely superseded by the SI unit, the ohm.

What does the 'ab-' prefix in 'abohm' mean?

It stands for 'absolute', indicating it belongs to the 'absolute' or electromagnetic system of cgs units.

Can I find 'abohm' in a modern physics lab?

Almost certainly not. All modern instruments and specifications use the SI ohm.

Is a nanohm the same as an abohm?

Numerically, yes: 1 abohm = 1 × 10⁻⁹ ohm = 1 nanohm. However, they belong to different measurement systems (cgs vs. SI), so they are not conceptually identical units.

abohm

Very Low

UK/æbˈəʊm/US/æbˈoʊm/

Technical/Scientific, Archaic

My Flashcards

Definition

Meaning

A unit of electrical resistance in the centimeter-gram-second (cgs) electromagnetic system, equal to one billionth of an ohm (10⁻⁹ ohm).

A historical scientific unit used before the adoption of the International System of Units (SI), specifically within the cgs electromagnetic unit system.

Linguistics

Semantic Notes

The term is formed with the prefix 'ab-' (from 'absolute') and 'ohm'. It belongs to the 'ab-' series of cgs electromagnetic units (e.g., abampere, abcoulomb, abvolt). It is now obsolete, having been superseded by the SI unit, the ohm.

Dialectal Variation

British vs American Usage

Differences

No significant regional differences in meaning or usage, as it is a purely technical, historical term.

Connotations

Connotes a specific, historical scientific context, often appearing in older physics and engineering texts.

Frequency

Extremely rare in contemporary use in both regions, limited to discussions of historical metrology or theoretical physics.

Vocabulary

Collocations

strong

cgselectromagnetic unitunit of resistance

medium

convert tomeasured inequal toless than one

weak

absolutesystemvalue ofuse the

Grammar

Valency Patterns

The resistance was [QUANTITY] abohm.One abohm equals 10⁻⁹ ohm.

Vocabulary

Synonyms

Strong

10⁻⁹ ohmnanohm (context-dependent, but note: 1 nanohm in SI = 10⁻⁹ ohm, a different but numerically equivalent modern unit)

Neutral

cgs unit of resistance

Weak

EMU of resistanceabsolute ohm (historical synonym)

Vocabulary

Antonyms

statohm (the corresponding unit in the cgs electrostatic system)

Usage

Context Usage

Business

Never used.

Academic

Found only in historical contexts within physics or electrical engineering literature; not in modern coursework.

Everyday

Never used.

Technical

Sole context: historical or highly specialised theoretical discussions of measurement systems and unit conversion.

Examples

By CEFR Level

An abohm is a very small unit for measuring electrical resistance.

The textbook explained that one abohm is equivalent to a nanohm in the SI system.

In the cgs electromagnetic system, the abohm serves as the base unit of resistance, defined such that one abvolt produces one abampere of current.

Learning

Memory Aids

Mnemonic

Think: 'ABsolute' OHM – the 'absolute' or fundamental cgs version of the ohm.

Conceptual Metaphor

N/A – It is a precise, technical measurement unit.

Watch out

Common Pitfalls

Translation Traps (for Russian speakers)

Не путать с просто 'ом' (Ω). 'Абом' — это конкретная, устаревшая единица в системе СГС, равная 10⁻⁹ современного ома.
Прямого аналога в современной системе СИ нет, кроме численного эквивалента 'наноом'.

Common Mistakes

Using it as a synonym for the modern SI ohm.
Misspelling as 'a-bohm' or 'ab-ohm'.
Assuming it is still a current unit.

Practice

Quiz

Fill in the gap

In the obsolete cgs system, the was the unit of electrical resistance.

Multiple Choice

What is the relationship between an abohm and an ohm?

FAQ

Frequently Asked Questions

: No, it is an obsolete unit from the cgs system, completely superseded by the SI unit, the ohm.
: It stands for 'absolute', indicating it belongs to the 'absolute' or electromagnetic system of cgs units.
: Almost certainly not. All modern instruments and specifications use the SI ohm.
: Numerically, yes: 1 abohm = 1 × 10⁻⁹ ohm = 1 nanohm. However, they belong to different measurement systems (cgs vs. SI), so they are not conceptually identical units.